A vehicle camera fixed on a vehicle is used for detecting an obstacle outside the car from a camera image and for parking support. In addition, it is possible from an image of the vehicle camera to acquire illuminance information indicating the brightness in the imaging range, and to decide the intensity of light at the site of the vehicle from the illuminance of the entire screen determined by the illuminance information. Using the decision result enables automatic turning on and off of the lights.
For example, a Patent Document 1 discloses an auto-light device comprising an imaging device for taking an image ahead of the vehicle, and a light control device for executing light control of turning on or off the lights in accordance with the image taken with the imaging device. The apparatus selects to turn off the lights when the brightness (cd/m2) in front of the vehicle is not less than a preset level 1 (first reference value), and to turn on the sidelights when the brightness is greater than a preset level 2 (second reference value) but is less than the level 1. When the brightness is less than the level 2, it selects to turn on the headlights.